Electrostatic precipitators



Jafi. 23, 1962 R. D. RIVERS 3,017,953

ELECTROSTATIC PRECIPITATORS Filed March 3, 1958 ll lr-6 I I II If FIG.l3

2 Sheets-Sheet 1 FIG.6 H65 ,4

FIGJZ INVENTOR. RICHARD D. RIVERS ATTORNEY i Tum! Jan. 23, 1962 R. o.RIVERS 3,017,953

ELECTROSTATIC PRECIPITATORS Filed March 3, 1958 2 Sheets-Sheet 2 FIG. l5

FIG.I6

FIG. l8 FIG.I9

INVENTOR.

RICHARD D. RIVERS QM Q. 624% ATTORNEY United States Patent oresEfil'ifiEB Faterrted Jan. 23, 1962 3,017,953 ELECTRUSTATICPREGIPITA'IORS Richard D. Rivers, Louisville, Ky, assignor to AmericanAir Filter Company, Inc, Louisville, Ky, 21 corporation of DelawareFiled Mar. 3, 1958, Ser. No. 718,647 4 Claims. (Cl. 183-7) Thisinvention relates to electrostatic precipitators and more particularlyto an improved plate electrode assembly for electrostatic precipitators.

In electrostatic precipitators of the type wherein electrostaticallycharged dust particles are passed into collector plates, such as is donein Dahlman Patent No. 2,486,521, it has been the practice to arrange thecollector plates into plate electrode assemblies with the plates of theassemblies being spaced from each other by a number of individualtubular spacer segments positioned between the plates and supported onrods which pass through openings in the plates.

The present invention provides an improved plate electrode assemblywhich includes all of the desirable features of past electrodeassemblies, and which, in addition, can be manufactured and assembledmore economically, rapidly and efficiently with a minimum of operatingsteps and with fewer materials. Further, the electrode assembly of thepresent invention is of such construction as to insure effectiveelectrical contact between the several parts of the assembly and to lenditself to ready removal and replacement for cleaning and servicingwhenever necessary.

Various other features of the present invention will become obvious toone skilled in the art upon reading the disclosure set forthhereinafter.

More particularly the present invention provides a plate electrodeassembly for an electrostatic precipitator comprising a plurality ofplates, the plates having openings therein, spacer bars extendingthrough the openings, the spacer bars having transverse slots thereininto which the plates extend, and key bars extending through theopenings to hold the plates in the transverse slots of the spacer barsand lock the plate assembly into desired position.

It is to be understood that various changes can be made in thearrangement, form and construction of the apparatus set forth hereinwithout departing from the scope or spirit of the present invention.

Referring to the drawings:

FIGURE 1 is a partial face elevation of a plate electrode assemblyarrangement which embodies the present invention;

FIGURE 2 is a partial side elevation taken in a plane passing throughline 2-2 of FIGURE 1;

FIGURE 3 is a face elevationof a portion of a spacer bar, disclosing thetransverse slots therein for spacing the plates of an assembly;

FIGURE 4 is a side elevation of the spacer bar of FIG- URE 3;

FIGURE 5 is a face elevation of a portion of 'a key bar which cooperateswith the spacer bar of FIGURES 3 and 4;

FIGURE 6 is a side elevation of the key bar of FIG- URE 5;

FIGURE 7 is an enlarged side elevation of a portion of a plate assembly,disclosing a spacer bar inserted into the plate openings;

FIGURES 8 through 12 are a series of schematic, partial face elevations,disclosing the progressive steps involved in assembling the plates,spacer bar and key of the electrode assembly;

FIGURE 13 is an enlarged side elevation, similar to that of FIGURE 7, ofa portion of a plate assembly, disclosing both key and spacer barsinserted and the plate assembly locked;

FIGURE 14 is an enlarged face elevation of a portion of the assembly ofFIGURE 1, disclosing an arrangement for fastening the key bars to theside plates of an assembly;

FIGURE 15 is a side view of the key bar of FIGURE 14;

FIGURE 16 is a schematic, partial face view of a modified arrangement ofthe present invention;

FIGURE 17 is a schematic, partial side view of the arrangement of FIGURE16;

FIGURE 18 is a schematic, partial side view of a further modification tothat of FIGURES l6 and 17; and,

FIGURE 19 is a schematic, partial side view of still anothermodification to that of FIGURES 16 and 17.

Referring to FIGURES 1 and 2 of the drawings, plate assembly 2, whichembodies the present invention, includes charged end plates 3 from whichare supported, intermediate thereto, charged plates 4. The chargedplates 4 are arranged in spaced, parallel relationship to each other andhave positioned in alternate arrangement therewith spaced, parallelgrounded electrode plates 5. The plates 5 are supported from groundedend plates 6 which, in turn, are attached to the housing of theprecipitator (not shown) and which support end plates 3 by means ofinsulators 7.

One of the principle features of the present invention is the structureused for supporting the intermediate electrode plate arrangements fromtheir respective end plates. Referring to FIGURES 3 through 13, detailsof one advantageous embodiment of such structure are disclosed. As canbe seen particularly in FIGURES 1, 2, 7 and 13, each electrode plate 4is provide with rectangular support openings 8 therein. It is to beunderstood that in one advantageous embodiment of the invention, foursuch openings can be provided in each plate. Plates 4 are loaded in ajig for proper parallel spacing and for proper alignment ofcorresponding support openings. When the plates are properly set in thejig, spacer bars 9 are inserted into aligned sets of openings. As can beseen in FIG- URES 3, 4 and 7 of the drawings, spacer bars 9 are of across sectional contour similar to the contour of support openings 8 tosnugly fit therethrough. Spacer bars 9, which can be die cast, are eachprovided with a plurality of spaced, transverse slots 11 on one sidethereof into which plates 4 extend, as will be seen hereinafter. On thesides opposite the transversely slotted sides of the spacer bars 9 areprovided longitudinally extending grooves 12. Designed to cooperate witheach spacer bar R is a key bar 14 (FIGURE 5 and 6). Each key bar 14 isprovided with a tongue 16 which is contoured to slidably engage with agroove 12 of a spacer bar 9, as will be seen hereinafter. It is to benoted that the cross-sectional depth of each key bar 14, includingtongue portion 16, is substantially equal to the depth of transverseslot 11 plus groove 12 in spacer bar 9.

With such an arrangement abovedescribed, it is possible to hold theelectrode plates of an assembly firmly in the slots and lock the plateassembly into desired position. It is to be understood that both thespacer bar and key bar can be cast, rolled or press formed and, in someinstances, even can be extruded from aluminum.

Referring to FIGURES 8 through 12 of the drawings which disclose thesteps involved in assembling the plates, spacer and key bars, plates 4are supported in a jig (not shown) in spaced relationship with supportopenings 8 in alignment, the spacing between plates being equal to thespacing of the transverse slots 11 in the spacer bar 9. Bar 9 then isinserted through the openings 8 until each slot 11 in the bar isopposite its matching plate 4 (FIG- URE 9). At this point, bar 9 islifted to engage plates 4 into slots 11 and to leave room for key bar14. Key bar 14 then is inserted with tongue 16 slidably engaging groove12 of spacer bar 9.

To fasten the spacer and key bar assembly to end plates 3, anarrangement can be provided wherein the ends of key bar 14 are tappedand single sheet metal screws 15 cooperate with such tapped ends to holdthe key bar to plates 3 (FIGURES 14 and 15). With the key and spacerbars properly in position in the assembly, the assembly is tightlylocked in place (FIGURE 13) to insure proper electrical contactthroughout and, as in a Chinese puzzle, the assembly cannot be moveduntil the key bars are removed.

It is to be noted that in inserting spacer bars 9 and key bars 11 intoopenings 8 of plates 4, provision is made in the form of cut aways 1.6in grounded plates and 6 (FIGURES 1 and 2) to permit such assembly andto provide proper electrical clearance where necessary. It further is tobe noted that grounded plates 5 and 6 can be provided with spacer andkey bar arrangements like that provided for charged plates 3 and 4 andthat charged plates 3 and 4 can, in turn, be provided with cut aways topermit proper insertion and clearance of the spacer and key bars for thegrounded plates.

Referring to FIGURES 16 through 19 of the drawings, there isschematically disclosed three further modifications which embody theprinciple of the spacer and key bar arrangement of the presentinvention. In these figures, support openings 18 in the electrode platesare substantially circular in shape and the spacer bars 21 which extendthrough such openings each comprise a longitudinal segment of acylinder, having an arc-like cross-sectional contour conforming to anouter portion of the circular opening with transverse slots 22 in thecurved, outer side of the segment into which the electrode platesextend. The key bars which cooperate with spacer bars 21 to hold theplates in the transverse slots 22 of spacer bars 21 when the spacer barshave been inserted into the plate openings are curved to nest with thecurved inner side of the spacer bars and are of a crosssection whichinsures a tightly locked final assembly. As can be seen in the drawings,these key bars can have various cross-sectional contours. In FIGURES 16and 17, key bar 23 is shown to have a circular cross-sectional contourof a diameter less than the diameter of opening 18. In FIGURE 18, keybar 24 is shown to have an elliptical cross-sectional contour the lengthalong the major axis of which is substantially equal to the diameter ofopening 18, to insure more bearing surface between key, plate, andspacer bar. And, in FIGURE 19, key bar 26 is of substantially circularcross sectional contour of a diameter substantially equal to diameter ofopening 18 and which is recessed or cut away to allow the key bar toconform with the inner surface of the spacer bar 21 to insure an almostcomplete bearing surface between plate, spacer and key bar.

It is to be understood that the spacer and key bar arrangements ofFIGURES 16 through 19 can be roll formed or extruded with no sawing, thekey bars serving to provide a ready orientation with the circularsupports openings 18 through which they are inserted for spacing theelectrode plates. In addition, electrical clearances can be easilyprovided with the arrangements of FIGURES 16 through 19 since there isno concentration of fields at the corners of the bars. As a result, thecut away portions in plates of opposite electrical sign need not be aslarge. Further, these circular type arrangements afford streamlinesurfaces to gas flowing through the precipitator to thus permit betterflow characteristics.

The invention claimed is:

1. A plate electrode assembly for an electrostatic precipitatorcomprising a plurality of spaced plates, said plates having openingstherein, a spacer bar extending through said openings, said spacer barhaving a crosssectional contour peripherally conforming with saidopenings except for a groove on one side of said spacer bar extendingparallel the longitudinal axis of said spacer bar, the opposite side ofsaid spacer bar having spaced transverse slots therein engageable withsaid plates adjacent the edges of said openings upon lateraltranslational movement of said spacer bar, and a key bar extending insaid groove of said spacer bar parallel thereto to hold said slots ofsaid spacer bar in engagement with said plates after said spacer bar hasbeen so laterally moved to lock the plate assembly into desiredposition.

2. A plate electrode assembly for an electrostatic precipitatorcomprising a plurality of spaced plates, said plates havingsubstantially rectangular openings therein, spacer bars extendingthrough said openings, each of said spacer bars having a cross-sectionalcontour peripherally conforming with said openings except for a grooveon one side of said spacer bar extending parallel to the longitudinalaxis of said spacer bar to fit therethrough upon initial insertion intosaid openings, said spacer bars further having transverse spaced slotson the sides opposite said grooves thereof engageable with said platesadjacent the edges of said openings upon lateral translational movementof said spacer bars, and key bars extending in said grooves of saidspacer bars parallel thereto, said key bars having a cross-sectionaldepth at least equal to the depth of said transverse slots in saidspacer bars to hold said slots of said spacer bars in engagement withsaid plates after said spacer bars have been so laterally moved to lockthe plate assembly into desired position.

3. The apparatus of claim 1, wherein said plate electrode assemblyincludes end plates positioned in spaced relationship on either side ofsaid plurality of spaced plates, and fastening means to fasten said keybar to said end plates.

4. The apparatus of claim 3, said fastening means including screwmembers passing through said end plates into the ends of said key bar.

References Cited in the file of this patent UNITED STATES PATENTS469,519 Hale Feb. 23, 1892 856,131 Canda June 4, 1907 1,140,657Benjamins May 25, 1915 1,697,316 Horny Jan. 1, 1929 2,542,262 RichardsonFeb. 20, 1951 2,642,952 Landgraf June 23, 1953 FOREIGN PATENTS 385,508Great Britain Dec. 29, 1932 749,290 France May 2, 1933 773,867 FranceSept. 10, 1934 893,555 Germany Oct. 15, 1953

